function(input, output) {
 
output$main_plot <- renderPlot({
 
hist(faithful$eruptions,
probability = TRUE,
breaks = as.numeric(input$n_breaks),
xlab = "Duration (minutes)",
main = "Geyser eruption duration")
 
if (input$individual_obs) {
rug(faithful$eruptions)
}
 
if (input$density) {
dens <- density(faithful$eruptions,
adjust = input$bw_adjust)
lines(dens, col = "blue")
}
 
})
}